Control system



Oct. 29, 1935. 1 R, ALLISON ET AL 2,019,063

CONTROL SYSTEM 3 Sheets-Sheet 1 Filed June 29, 1931 L\ INVENTORS N M. W. A BY MTTORNEY Ina/say Q-m/JWM Oct. 29, 1935.

L. R. ALL ISON ET AL CONTROL SYSTEM Filed June 29, 1931 3 Sheets-Sheet 2 INVENTORS AIR. Pr/ lx'son,

M. W. kl ndsay, BYM ATTORNEY Oct. 29, 1935. R. ALLISON ET AL CONTROL SYSTEM Filed vJune 29, 1931 5 Sheets-Sheet 3 INVENTORS W. L l ndsay xi N BYWATTCRNEY Patented Oct. 29, 1935 PATENT OFFICE CONTROL SYSTEM Leslie R. Allison, Forest Hills, and Norman Ward Lindsay, Pittsburgh, Pa., assignors to The Union Switch & Signal Company, corporation of Pennsylvania Swissvale, Pa., a

Application June 29, 1931, Serial No. 547,672

5 Claims.

This invention relates to control systems, and, although it has been primarily designed for employment in connection with brake-control means on trains, its utility is by no means to be limited to such function as it is susceptible of use in other fields.

The main object and feature of the invention is the provision of means for testing or indicating the integrity of one or more circuits that control normally deenergized translating means without, however, energizing said translating means when testing the circuit or circuits.

In the accompanying drawings the invention is disclosed in several concrete and preferred forms, in which:

Fig. l is a diagrammatic view of circuits that constitute one form of the invention:

Fig. 2 is a diagrammatic view similar to Fig. 1 showing a modified form of the invention:

Fig. 3 is a diagrammatic view similar to Figs. 1 and 2 showing a second modified form of the invention: and

Fig. 4 is a detail view of a rectifying means that may be employed in connection with the arrangements shown in Figs. 1 and 3.

The construction shown in Fig. 1 will first be considered.

In the exemplification shown in the drawings, there are two circuits .which here have one path in common, said path being conveniently indicated by conductor C, reference characters A and B indicating line wires which in conjunction with common path C and other devices to be presently described constitute two line circuits. These line circuits may be conceived as extending from a control station D to a remote station E, and in the present instance said control station is one of a plurality of cars, such as the cab of the engine, and said remote station is another one of a plurality of cars, such as the caboose of a train. Any

number of intervening cars may, of course, be present, and it will be seen that the line circuits extend from car to car. M indicates a translating device, here a traffic-controlling device such as a brake-control magnet, connected across conductors A and C. M indicates a similar translating device connected across conductors B and C. M and M are of the type of brake-control means that are normally deenergized, and which when energized apply the brakes. Any suitable means may be provided to energize M and M In the present instance is shown a source of direct current 0 having one lead 0 connected to path C and the other lead 0 connected through wires 0 and 0 to either one or both of line conductors B and A. The arrangement is here such that when the engineers brake valve V is in the position shown in the drawings, that is in release,

7 running or holding position, the contacts are open When valve V is moved into 10 1! It will be understood that with such construc- 0 tion it is desirable to provide meansfor testing the integrity of the line conductors so that the engineer may be assured at all times that the brakes will function if operated. Also,

of the brakes.

Accordingly, ,the following means, or 011611 equivalent, are provided to test the integrity of 2 the line circuit:

Any suitable means may be employed to supply I current, of a character different from that supplied by source O, to the line conductors, said [means taking here the form of a transformer T,

the secondary of which is included in line conductor C. I and 4 indicate two quick-release alternating current relays, one on the engine and the other on the caboose, which are connected in series with each other and conductors A and C. 2 and 3 indicate two additional quickrelease alternating current relays, one on the engine and the other on the caboose, connected in series with each other and conductors B and 0. While four single element relays have been 40 shown it will be obvious that, instead thereof, two double element relays of the dynamic type, one on the engine and one on the caboose, may be used. Each of said relays controls an armature ture I2, wire 29, armature II, wire 26, coil of relay I, wire 24, conductor A, wire 34, coil of relay 4, wire 36, armature I6 and conductor C back to secondary of T. Current will also flow from wire 26, to coil of relay 2, over wire 25, conductor B, Wire 33, coil of relay on long 20 freight trains, it is desirable that the crew in the caboose be kept informed as to the dependability or circuit breaker (I I, I2, I6 and I1) the circuits 45 3, wire 35, arma- 'relay 5 thereof picking up armature ture I1 and wires 31 and 59, conductor C and back to secondary of transformer T. Thus relays I and 4 are in multiple with relays 2 and 3, and it will be evident that a break or other defect in any of the line conductors, with the consequent deenergization of any one of relays I, 2, 3 and 4, will cause all of armatures II, I2, I6 and I1 to drop thereby rupturing the entire system so far as the flow of testing current from secondary of transformer T is concerned. Obviously relays I, 2, 3 and 4 and their armatures may be considered indicating means, but it is preferred to have indicating means in addition to said relays and also to provide signaling means. Such additional indicating and signaling means can conveniently be coordinated with shunting devices for starting the system in operation, and in the present instance take the following form: D is an indicating device, on the engine, such as a lamp which receives current from any suitable source,

such as a battery connected to points B and B over wires 3I and 21, armature I3 of relay I, wire 39, armature I4 of relay 2, and wire 32. Connected inmultiple with light D is a direct-current slow-release relay 5. 28 indicates a shunt around armatures II and I2, said shunt having two branches, one, 28 leading over armature I5 of relay 5, and the other, 28*, leading through switch 8. E is an indicating device, on the caboose, such as a lamp which receives current from any suitable source, such as a battery connected to points B and B over wires 39 and 38, armature I8 of relay 3, wire 43 and armature I9 of relay 4. Connected in multiple with lamp E is a direct-current slow-release relay 6. A shunt is provided around armature I6 consisting here of wire 5| leading from wire 36, armature 23 (and its back contact) of relay 1, and wire 59 leading to conductor C, and this shunt has another branch or parallel path 36 connecting wires 5I and 50, and leading through armature 20 of relay 6. Relay 1 is here energized, by means of current received from battery B B ,-over wires 39 and 40, armature 2I of relay 3, wire 4|, armature 22 of relay 4, and wire 42. As indicated, relay 1 is a direct-current slow-release relay, the release period of which is greater than that of relay 6.

9 and I indicate two signaling keys in conduc- 'tor C.

1 Let it be assumed that all relays are deenergized and all armatures are down, that keys 9 and. I0 are closed and switch 8 is open. To. set the system in operation, switch 8 is closed and, as armature 23 of relay 1 is in its down-position against its back contact, the following circuit will be established: current from secondary of transformer T will flow over shunt 28 and branch 28 thereof, over switch 8, along wire 26 to coil of relay I, over wire 24, conductor A, wire 34, coil of relay 4, over wires 36 and I, armature 23 of relay 1, wire 50, and conductor C back to secondary of transformer T. The effect of this is to pick up armatures II and I3 of relay I, and armatures I1, I9 and 22 of relay 4. This permits current to flow from wire over wire 25, conductor B, wire 33, coil of relay 3, wire 35, armature I1 of relay 4, wires 31 and '50, and conductor C back to secondary of transformer T. The result of this is to pick up armatures I2 and I4 of relay 2, and armatures I6 I8 and 2I-of relay 3. The further result of this is (in the engine) to light lamp D and to energize I5, and (in the caboose) to light lamp E to energize relay 6 to thereby pick uparmature 20, and to energize 26 to coil of relay 2,,

be opened momentarily to send signals from the 5 engine to the caboose or vice versa. The effect of this momentary opening of a key like 9 or II) is to deenergize relays I, 2, 3 and 4 thereby dropping their armatures and to extinguish lights D and E Slow-release relays 5 and 6 will, however, remain energized long enough to hold armatures I5 and 29 in their up-position if key 9 or I0 is again moved to its closed position quickly enough. The result is that when key 9 or III is again closed current will flow as previously described in connection with the placing of the system in operation, except that, instead of passing over switch 8 on the engine and over armature 23 of relay 1 on the caboose, the current will flow over armature I5 of slow-release relay 5 39 of the engine, and over armature of slow-release relay 6 of the caboose. Therefore, all the relays will again become energized and lamps D and E will be lighted.

Suitable blocking or filtering means, such as 5 are well-known in the art, may be inserted in the various leads to segregate the current of source 0 from that delivered by source T. For instance, choke coils I6 may be inserted in leads 0 and 0 and magnets M and M can be protected from 30 the alternating current by having a high impedance, and condensers C C C and C can be inserted in wires 24, 25, 33 and 34 to protect the relays from the direct current of source 0. In the present instance, said condensers serve 35 the additional purpose of tuning out the reactance of relays l, 2, 3 and 4 to thereby reduce the voltage required. from transformer T, and also reduce the shunting effect of magnets M and M.

From the foregoing, it will be understood that any defect in the system that will cause one or more of relays I, 2, 3 and 4 to become deenergized and to remain deenergized for a longer. period than the release time of relays 5 and 6 will cause the whole system to become deenergized, so far as the testing current is concerned, and will give indication of this condition both on the engine and caboose. Such defects, or failure in the integrity of the circuits, may be caused by an open or rupture in one of the three conductors A, B and C, by a short-circuit between conductors A and C, or by a short-circuit between conductors B and C. A short-circuit between conductors A and B would not be detected, because these two conductors are at the same potential, but since said conductors are so to speak tied together when the engineers brake valve is in the position where contacts '0 v and o engage contacts 12 o and 'v,

a service application of the brakes can be effected notwithstanding the existence of such so short-circuit and therefore its detection is not very essential. The integrity of condensers C C C and C is likewise. checked by the testing current and any defect detected. Thus an open" in any of the four condensers will deenergize the 05 relays in the same way that any open in any of the wires would, and a short-circuit in a condenser will detune its associated relay and will reduce the current in such relay below the release value of such relay. It has been pointed out that the slow release period of relay 1 is of greater duration than that of relay 5, and the reason for this will now be pointed out in detail. If, for instance, a short-circuit should develop between conductors B and C, then relay 3 would not reiii connection with Fig. 1.

ceive current sufficient to energize it, and consequently armatures I6 I8 and 2| would drop. This would cut-off current both to relays 6 and I, and if relay 7 should drop its armature 23 earlier or at the same time that relay 6 drops armature 20, it will be evident that a shunt would be created around armature I6 over wires 36 and SI, armature 23 and its back contact and wire 50 to conductor C. Relays I, 2 and 4 would therefore remain energized and the defect or shortcircuit would not be detected. By making relay 1 slower in its release than relay 6, contact 23 will not drop and close the shunt, at that point, until it is certain that relay 3 has broken (at I6 the circuit of relay 4 a suflicient length of time to cause relays I and 4 to drop their armatures and to thereby indicate the defect in the circuit means. The arrangement just described has, however, a disadvantage in that if relay 7 for any reason fails to pick up armature 23, then a, permanent shunt will exist around armature I6 and if a short-circuit should develop between conductors B and C, relays I, 2 and 4 would fail to release.

In order to overcome this objection the arrangement shown in Fig. 2 may be used. In Fig. 2 the equipment carried by the engine is the same as that previously described in connection with Fig. l, the same three conductors A, B and C are retained and the same relays 3 and 4 are employed. In this case, relay 70, which corresponds to relay 1 of Fig. 1, is normally deenergized, and relay 60, which corresponds to relay 6 of Fig. 1, is a quickrelease relay. In the modification shown in Fig. 2, armatures I60, I10, 200 and 2I0 cooperate with front contacts in a manner similar to armatures I6 I'I, 2I and 22 of Fig. l. Armatures I and I90, which correspond to armatures I8 and I9 of Fig. 1, cooperate with back contacts. Armature 230, which corresponds toarmature 23 of Fig. 1, cooperates with a front contact, and armature 220, which corresponds to armature 20 of Fig. 1, is placed under the control of relay 60 and engages a back contact. It will now be seen that, when relays 3, 4 and 60 are deenergized, current will flow from a battery, connected to points B and B over wire 52, armature I90 and its back contact, to wire 53, armature I80 and its back contact, wire 54, relay I0, wire 55, armature 220 and its back contact and wire 56. This energizes relay I0, picks up arma ure 230 and closes the shunt at that point. If switch 8 is now closed, current will be supplied from the secondary of transformer T to relays I and 4, as explained in But from relay 4 the current will flow over wire 57, armature 230 and wire 58 to conductor C thereby picking up armatures I10, I90 and 2I0. This will permit current to flow from secondary of transformer T, in the manner described in connection with Fig. 1, to relays 2 and 3 and from the latter over wire 59 and armature I10 to conductor C, thereby picking up armaiures I60, I80 and 200. Current will now flow from the battery, connected to points B and B over wire 52, wire 6I, armature 2I0, wire 62, armature 200, wire 63, in multiple through relay 60 and light E and over wire 64. Armature 220 will now be picked up, and, after the release time of relay 10 has expired, armature 230 will drop. It will now be understood that if for any reason relay 10 should fail to pick up its armature 230 it will not be possible to start the system in operation and lights D and E will not be energized. Signaling by means of key 9 or III can also be carried on in the system of Fig. 2.

If one of said keys is opened relays I, 2, 3 and 4 will become deenergized thereby dropping armatures II, I2, I3, I4, I60, I10, I80, I90, 200 and 2I0. This will deenergize relay 60 and extinguish lights D and E Relay I0 will now pick up its armature 230 thereby establishing the shunt around armature I60. If the key is now closed before the release period of relay 5 expires it will be evident that the shunt over armature I5 will have been maintained, and therefore relays I, 2, 3, 4 will again become energized, relay 60 and lights D and E will likewise become energized and relay I0 will become deenergized.

In Fig. 1, the direct current utilized in energizing the caboose equipment is described as coming from a battery connected to leads B and B. It will be understood, however, that it is immaterial how this current is obtained. For instance, as shown in Fig. 4, direct current could be obtained from two rectifiers, one R connected between conductors B and C, and another R connected between conductors A and C. In this instance lead B is connected to rectifier R from whence leads a wire r to rectifier Rand from the latter leads another wire 1' back to rectifier R and to lead B It will be obvious that the current used to test the circuit need not be alternating current, and that the current used to actuate the brake-control means need not be a direct current; it is sufficient if the two currents have such different characteristics as to permit them to be readily segregated.v In Fig. 3 is shown the same layout as in Fig. 1, except that alternating current is used to energize the brake control means and direct current is used for testing purposes. In other words: a battery 44 is used in place of transformer T and leads B and B can then still receive current from a separate battery as in Fig. 1 or they can be connected on opposite sides of battery 44 as will be evident. To prevent the flow of alternating current in the direct current relays, tuned impedances I I I and I are inserted in wires 24, 25, 33 and 34. Relays 6 and I and lamp E can receive direct current in the manner described in connection with Fig. 1 or relays 6, I and lamp E can be connected to wire 50 in which event wire 42 is connected by a wire to wire 34 and to tuned impedance I In order to protect the brake-actuating relays M and M from the direct current used for testing purposes, condensers C are placed in series With said relays. Wires 0 0* and 0 lead to an alternating source of current through an engineers valve similar to that shown at V in Fig. 1, but choke coils I6 are omitted.

It is considered unnecessary to trace the cirsuits that arise under various operating conditions in Fig. 3, as it would be practically a repetition of the description associated with Fig. 1. The circuit of Fig. 3 has one advantage over that shown in Fig. l in that the brake-operating magnets constitute no load whatever on the current source (here battery 44) that supplies the testing current.

We claim:

1. A control system including two line conductors and a common path all extending between two stations, two relays at each station, a. first circuit including one of said conductors and the winding of the first relay at each station as well as said common path and a front contact of each relay at the first station and a front contact of the second relay at the second station, a second circuit including the other of. said conthe second station,

. shunt around said front contacts of' ductors and the winding of the second relay at each station as well as said common path and a front. contact of each relay at the first station and a front contact of the first relay at the sec,- ond station, a shunt around said front contacts of the relays at the first station including a normally open manually closable switch, a shunt around said front contact of the second relay at and means for closing said second shunt when either or both of the relays at the second station are deenergized.

2. A control system including two line conductors and a common path all extending between two stations, two relays at each station, a first circuit including one of said conductors and the winding of the first relay at each station as well as said common path and a front contact of each relay at the first station and a front contact of the second relay at the second station, a second circuit including the other of. said conductors and the winding of the second relay at each station as well as said common path and a front contact of each relay at the first station and a front contact of the first relay at the second station, a the relays at the first station including a normally open manually closable switch, a shunt around said front contact of the second relay at the second station including a back contact of a fifth relay, and a circuit for the winding of said fifth relay including a front contact of each of the other relays at the second station.

3. A control system including two line conductors and a common path all extending between two stations, two relays at each station, a first circuit including one of said conductors and the winding of the first relay at each station as well as said common path and a front contact of each relay at the first station and a front contact of the second relay at the second station, a second circuit including the other of said conductors and the winding of the second relay at each station as well as said common path and a front contact of each relay at the first station and a front contact of the first relay at the second station, a shunt around said front contacts of the relays at the first station including a normally open manually closable switch, a shunt around said front contact of the second relay at the second station including a front contact of a fifth relay, a sixth relay located at the second station, a circuit for the winding of said sixth relay including a front contact of each of the first two relays at the second station, and a circuit for the winding of said fifth relay including a back contact of each of the first two relays at the second station as well as a back contact of said sixth relay. 4. A control system including two line conductors and a common path all extending between two stations, two relays at each station, a first circuit including one of said conductors and the winding of the first relay at each station as well as said common path and a front contact of each relay at the first station and a front contact of the-second relay at the second station, a second circuit including the other of said conductors and the winding of the second relayat each station as well as said common path and a front contact of each relay, at the first station and a front contact of the first relay at the second station, a shunt around said front contacts of the relays at the first station including a normallyopen manually closable switch, a shunt around said front contact of the second relay at the second station, means for closing said second shunt when either or both of said relays at the second station are deenergized, an auxiliary shunt around said front contacts of said relays at the first station including a front contact of a slow releasing relay, a circuit for the winding of said slow releasing relay including front contacts of the first relays at the first station, a second auxiliary shunt around said front contact of the second relay at the second station including a front contact of a second slow releasing relay, a circuit for the winding of said second slow releasing relay including front contacts of the first two relays at the second station, manual means at one of said stations for opening both of said first mentioned circuits, and an indicator at the other station controlled by the first two relays at such station. 7

5. A control system including two line conductors and a common path all extending between two stations, two relays at each station, a

first circuit including one of said conductors and the winding of the first relay at each station as well as said common path and a front contact of each. relay at the first station and a front contact of the second relay at the second station, a second circuit including the other of said conductors and the winding of the second relay at each station as well as said common. path and a front contact of each relay atthe first station and a front contact of the first relay at the second station, a shunt around said front contacts of the relays at the first station including a normally open manually closable switch, a shunt around said front contact of the second relay at the second station, including a front contact of a slow releasing relay, means for energizing said slow releasing relay when the first two relays at the second station are open, an auxiliary shunt around said front contacts of said relays at the first station including a front contact of a. slow releasing relay, a circuit for the winding of said slow releasing relay including front contacts of 5 the first relays at the first station, manual means at one of said stations for opening both of said first mentioned circuits, and an indicator at the other station controlled by the first two relays at;

such station.

LESLIE R. ALLISON. NORMAN WARD LINDSAY. 

